Attorney General Jeff Sessions recently suggested he could resign amid a souring relationship between himself and President Donald Trump, sources told ABC News Tuesday.

The news outlet reported that the “friction” between the president and his attorney general stems from Sessions’ March decision to recuse himself from the investigation into Russian election meddling and all campaign-related inquiries.

Multiple sources told ABC that the recusal is “one of the top disappointments” of Trump’s presidency. ABC’s sources said Trump “has remained fixated on it,” and two sources said Trump has “lashed out repeatedly” at Sessions privately, pointing at his decision to recuse himself as the reason for the escalation in the Russia investigation. Former FBI Director Robert Mueller, who last month was appointed special counsel by Deputy Attorney General Rod Rosenstein, now oversees the investigation.

The tense relationship between the two men “runs both ways,” ABC wrote, adding that Sessions’ sentiment prompted his resignation offer. Sessions was the first senator to publicly endorse Trump and has been one of his most loyal backers. Trump rewarded Sessions after his election with one of the most coveted jobs in any administration, the opportunity to lead the Justice Department.

Sarah Isgur Flores, a Justice Department spokesperson, declined to comment on the ABC story when emailed by Business Insider.

Earlier Tuesday, White House press secretary Sean Spicer said he could not answer when asked if Trump still has confidence in Sessions.

“I have not had that discussion with him,” Spicer said. He later added, after being pressed again on the matter: “I said I have not had a discussion with him on the question. I don’t, If I haven’t had a discussion about a subject, I tend not to speak about it.”

The reportedly deteriorating relationship between Trump and Sessions was first reported by The New York Times, which said Monday that Trump was placing blame on Sessions for “various problems” that faced his administration.

On Monday morning, Trump took aim at the Justice Department on Twitter for its defence of his controversial travel ban on six Muslim countries, which is currently blocked by the courts. Trump seemed to blame the DOJ for the “politically correct” revised version of the order, which Trump himself signed, posting that the Justice Department “should have stayed with the original Travel Ban, not the watered down, politically correct version they submitted” to the Supreme Court.

The Times reported that Trump “has intermittently fumed for months over” Sessions’ recusal from all Russia matters, citing individuals close to the president. That recusal is connected “in some way” to “much of the past two months of discomfort and self-inflicted pain for Trump,” the Times wrote.